Cyclospora Outbreak
The Iowa Department of
Public Health is investigating a large outbreak of cyclosporiasis – a rare intestinal
illness. As of Aug. 14, 2013, 155 cases have been identified in 39 Iowa counties. The
State Hygienic Laboratory is conducting the confirmatory testing. There are now cases in 20 states and New York City. Public health officials in these states are investigating to identify possible common exposures. There has been no determination that cases in all states are related to the same source.
Interviews with ill individuals and subsequent food trace back investigations have led to the identification of a pre-packaged salad mixture as the source of Iowa’s outbreak. More than 80 percent of Iowa’s cases reported eating the same pre-packaged salad mix that contained iceberg and romaine lettuce, red cabbage, and carrots. The mixture entered Iowa already packaged and already contaminated. “The process that led to the implication of the pre-packaged salad mixture as the outbreak source is a good illustration of how public health investigations work,” said IDPH Medical Director, Dr. Patricia Quinlisk.
The symptoms of cyclosporiasis are distinct from other diarrheal illness in that symptoms last an average of 57 days in immune-competent patients, who may have five to 15 bouts of watery diarrhea per day. Fatigue and anorexia are prominent and other symptoms include nausea, flatulence, abdominal cramping, low-grade fever and weight loss. Persons who are immune-compromised will have more severe and longer lasting symptoms.
Cyclosporiasis is caused by the microscopic parasite Cyclospora cayetanensis. People can become infected with Cyclospora by consuming food or water contaminated with the parasite. Cyclosporiasis is not spread person-to-person.
In the United States, foodborne outbreaks of cyclosporiasis, identified since the mid-1990s, have been linked to various types of imported fresh produce, including raspberries, basil, snow peas and mesclun lettuce. No commercially frozen or canned produce has been implicated.
If you are experiencing symptoms consistent with Cyclospora infection, contact your physician. Diagnosis of cyclosporiasis can only be accomplished by a laboratory test. Your physician will provide an appropriate specimen collection kit and submission form which will then be sent to the Hygienic Laboratory for testing. Additional information is available on the IDPH website.
CDC: "Investigation of an outbreak of cyclosporiasis in the United States"
Health Care Providers:
Updated guidelines for determining if Cyclospora testing is appropriate for your patient have been issued by the Iowa Department of Public Health.
IDPH and SHL are recommending that healthcare providers use the following criteria to determine whether Cyclospora testing of patients is appropriate. Patients should be tested for Cyclospora only if:
- Patient's diarrhea began in June, or
- Patient has prolonged diarrhea (greater than 5 days duration - eliminating the more common causes of diarrheal illness), accompanied by symptoms such as fatigue and anorexia, or
- Patient is a traveler with watery diarrhea returning from a part of the world where Cyclospora is endemic (such as Nepal, Guatemala or Peru).
Stool specimens for Cyclospora testing submitted to the State Hygienic Laboratory must be in transport media suitable for parasitology testing and be accompanied by a physician order (completed test request form). Appropriate transport media includes 10 percent formalin or other commercial transport media specifically designed for parasitology testing.
Health care providers or clinical laboratories can order O&P specimen collection kits from the Hygienic Laboratory website. When submitting a specimen for testing, ensure that you have included a properly completed test request form. Use the Hygienic Laboratory Bacteriology test request form and select “Cyclospora” under Special Stains in the Parasitology section of the form. If you have any questions regarding testing, please call the Hygienic Laboratory at 319-335-4500.
Cyclospora Testing Update for Laboratory Professionals:
The following is a compilation of questions received during the outbreak and some additional information to help make the testing process as efficient as possible.
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If a specimen has been submitted for routine O&P/Trichrome testing in addition to the Cyclospora-specific stain and the Cyclospora test is positive, please contact us whether or not provider still needs the O&P/Trichrome testing.
If the provider is looking solely for Cyclospora and indicates that the routine O&P/Trichrome test can be canceled if Cyclospora has been identified, please email mary-demartino@uiowa.edu directly with your facility name and address, including city, and the statement listing the provider's name as shown below:
"____________(provider) has determined that SHL is permitted to cancel routine O&P/Trichrome testing for the provider's patients whose Cyclospora test is positive."
The same modified acid-fast stain is used for Cyclospora and Cryptosporidium so if Cryptosporidium is found during the examination, it will also be reported. There will still be a result issued stating whether or not Cyclospora was found.
